This is a set of agreed upon rules by members of the European Union that define the acceptable limits for the emissions from exhaust of new vehicles sold in the region. The common thread in all these standards is progressing increase in compliance requirements, thus increasing standards for acceptable emissions from vehicles.

Each vehicle type has a different standard that applies. The way to determine compliance is by running the vehicle's engine at a standardized test cycle. The standards set do not apply to vehicles already in use in the EU but only to new vehicles to be sold or prospectively. There is no specific technology devised to adhere to the standards but only available technology would be used to determine the standards to be applied to future vehicles.

These standards have been determined after a study found that nearly 20% of CO2 emissions are generated by road transportation and 12% are said to come from passenger cars. Overall, the European Union accounts for 3.5% of the CO2 total global emissions. As a signatory to the Kyoto Protocol, an agreed 8% reduction in emissions has been agreed to between 2008 and 2012. Hence these emissions resulting from Directive 1999/94/EC of the European Par
liament were established.

The goal is not to curtail the creating of cars but what is required is to provide information about fuel economy and CO2 emissions of new passenger cars sold in the European Union. This information provided would then allow the consumer the free and informed choice as to the proper vehicle to be purchased for their needs.

The legal framework is a series of guidelines and amendments to the original directive of the EEC. The following is a list of the standards provided and their probable future as a means of curtailing vehicle emissions in cars to be sold in the EU.

1. Euro 1 (1993). The standards for passenger cars is contained in 91/441/EEC and 93/59/EEC;

2. Euro 2 (1996). For passenger cars, the standards are in 94/12/EC and 96/69/EC while for motorcycles would be 2002/51/EC (row A) and 2006/120/EC;

3. Euro 3 (2000) for any vehicle would be in 98/69/EC and for motorcycles in 2002/51/EC (row B) and 2006/120/EC;

4. Euro 4 (2005) for any vehicle contained in 98/69/EC and 2002/80/EC;

5. Euro 5 (2008/9) and Euro 6 (2014) for light passenger vehicles while commercial vehicles can be found in 715/2007/EC;

The provided limits modify and supersede the emission limits originally set in 70/220/EEC.